Effects of Dexamethasone on Mucins of Human Corneal Epithelial Cells

ABSTRACT

PURPOSE: To evaluate whether mucin gene expression is regulated by glucocorticoid hormone in cultured human corneal epithelial cells (HCECs). The effects of dexamethasone on the expression of MUC1 and MUC4, two known mucins produced by corneal epithelial cells, were determined. METHODS: HCECs were cultured in medium supplemented with dexamethasone. The modulations of MUC1 and MUC4 expression by dexamethasone were investigated by RT-PCR and Western blot analysis. RESULTS: The expression of MUC1 mRNA and its protein were enhanced in HCECs by dexamethasone. However, the treatment of HCECs with dexamethasone caused a decrease in MUC4 mRNA and its protein. These effects of dexamethasone on the MUC1 and MUC4 were abolished by a glucocorticoid antagonist (RU486). CONCLUSIONS: This study shows that dexamethasone is implicated in the expression of mucin in HCECs, and suggests that glucocorticoid receptor participates in the modulation of mucin production.